Apparatus for inspecting display panel and method for inspecting display panel

Abstract

An apparatus for inspecting a display panel includes a light source, a half mirror reflecting a first beam which is a portion of a source beam irradiated from the light source and transmitting a second beam which is another portion of the source beam toward a display panel, a reflective mirror reflecting the second beam transmitting the half mirror and the display panel to return to the half mirror, a panel supporter supporting the display panel between the half mirror and the reflective mirror, a wave plate disposed between the half mirror and the reflective mirror and transmitting the second beam, a rotator rotating the wave plate at a predetermined angle and an imaging detector photographing an interference fringe by the first beam and the second beam.

What is claimed is: 
     
         1 . An apparatus for inspecting a display panel, the apparatus comprising:
 a light source;   a half mirror directly receiving a source beam from the light source and reflecting, by an upper surface of the half mirror directly facing the light source, a first beam which is a portion of a source beam irradiated from the light source and transmitting a second beam which is another portion of the source beam toward the display panel;   a reflective mirror reflecting the second beam transmitting the half mirror and the display panel to return to the half mirror;   a panel supporter supporting the display panel between the half mirror and the reflective mirror;   a wave plate disposed between the half mirror and the reflective mirror and transmitting the second beam;   a rotator rotating the wave plate at a predetermined angle; and   an imaging detector directly receiving the first beam from the upper surface of the half mirror and photographing an interference fringe by the first beam and the second beam.   
     
     
         2 . The apparatus of  claim 1 , wherein the panel supporter fixes the display panel not to rotate. 
     
     
         3 . The apparatus of  claim 1 , wherein the imaging detector photographs the interference fringe by the first beam and the second beam, wherein the first beam is reflected by the half mirror, and the second beam transmits the half mirror, the wave plate, and the display panel, is reflected by the reflective mirror, and again transmits the display panel, the wave plate, and the half mirror. 
     
     
         4 . The apparatus of  claim 3 , wherein the imaging detector acquires a first image obtained by photographing the interference fringe by the first beam and the second beam before the wave plate is rotated at the predetermined angle, and acquires a second image obtained by photographing the interference fringe by the first beam and the second beam after the wave plate is rotated at the predetermined angle. 
     
     
         5 . The apparatus of  claim 1 , wherein the wave plate is disposed between the half mirror and the display panel. 
     
     
         6 . The apparatus of  claim 1 , wherein the wave plate is disposed between the display panel and the reflective mirror. 
     
     
         7 . The apparatus of  claim 1 , wherein the light source irradiates a circularly polarized source beam. 
     
     
         8 . The apparatus of  claim 1 , wherein the reflective mirror is inclined with respect to the half mirror.